Plotter.



Patented Sept. 20, 1910;

62W @/we G. H. GROVE.

PLOTTER.

APPLICATION FILED JAH. 10, 1910.

Wbt/heee@ 'ml Nouns Parlns co.. wAsHlNafoN. D. cy

UNITED sTATEs PATENT OFFICE.

PLOTTER.

specification of Letters Patent. Patented Sept. 20, 1910.

Application filed January 10, 1910. Serial No. 537,293.

To all whom it may concern:

Be it known that I, GEORGE I-I. GROVE, a

citizen of the United States, residing at Harrisburg, in the county ofDauphin and State of Pennsylvania, have invented certain new and usefulImprovements in Plotters; and I do declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to improvements in plotters.

The primary object of this invention is to provide a plotter by means ofwhich perspective drawings may be projected from geometrical views morequickly and with a greater degree of accuracy than by anyotherinstruments of like character now in vogue.

A second object of the invention is to provide a plotter which may beused as a T- square.

In the accompanying drawings, Figure 1 is a top plan view of a plotterembodying my improvements, the dotted lines indicatingthe position ofthe inner end of the marking ruler when swung at an angle to theperpendicular. Fig. 2 is a bottom plan view of a portion of theinstrument on an enlarged scale. Fig. 3 is a longitudinal section takenon the line 3-3 of Fig. 1, and Fig. 4 is a transverse section taken onthe line 1 -4.

Referring to the drawings for a more particular description of theinvention, which drawings are for illustrative purposes only 'and aretherefore not drawn to scale, the horizontal ruler 1 is preferablymounted upon the drawing board or table in the manner shown in myPatent, Number 927,526. This, of course, however, is not essential tothe operation of my plotter. A track bar 2 is attached to the face ofthe horizontal ruler 1 by the screws 3, or other equivalent means, andupon this track bar is mounted to slide longitudinally the adjustingslide bar 4. The bottom face of the slide bar is suitably recessed outto receive the track bar 2 and may be provided with a thumb screw 5,whereby the slide bar may be held at any desired adjustment. Projectingfrom the bottom and inner edge of the slide bar is a bearing extension6, which is preferably cut or recessed out as at 7 and 8, for lightnessand ornamentation. The outer end of the bearing extension is formed witha semi-circular portion 9, the edge of which is preferably beveled andgraduated as at 10, to provide for the adjustment of the marking ruler11, at the desired angle.

The marking ruler is formed from a single flat strip of metal or otherlike material which is cut out as at 12, providing the marking edges 13,which diverge from their inner ends toward the outer end of the ruler.The ruler may be further cut out as at 15, for the purpose of lightnessand ornamentation, if desired. The inner end of the marking rulerprojects somewhat inwardly beyond the semi-circular portion 9 of thebearing extension and is provided near one of its inner corners, with anaperture 16, provided for the reception of the pin or extension 16 ofthe locking bar 17, which is pivoted upon the face of the bearingextension and is provided with a inger-piecelS, whereby the pin orextension of the lockino' bar may be engaged with or disengagec from theaperture 16 of the marking ruler. Vhen the locking bar is thus engagedwith said aperture of the marking ruler, the latter is heldperpendicular with relation to the horizontal ruler 1, and theinstrument may be used in the capacity of a T-square. The marking ruleris pivoted to the bearing extension of the slide bar by the pivot screw19 passing through said ruler and extension and the wing nut 2O screwingon the threaded end of said screw against the face of the semi-circularportion of said bearing extension. By means of the wing screw justreferred to, the marking ruler may be held at any angular adjustmentduring the operation of projecting the plotter from a geometrical view,which operation is greatly facilitated by the diverging marking edges ofthe ruler. The inner end of the marking ruler is beveled inwardly as at21, is slightly convex, and slides against the correspondingly bevelededge of the guide recess 23, formed by the cross bar 24. l

From the foregoing description taken in connection with the accompanyingdrawings, the construction and operation of fthe invention will bereadily understood Without requiring a more extended explanation.

Various changes inthe form, proportion and the minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the advantages of the invention, as defined in theappended claims.

What is claimed as new is l. An instrument of the class described,

Va marking ruler pivotedv intermediate its ends upon the bearingextension provided with a pair of inside marking edges which divergefrom the inner ends outwardly pivoted to the extension of the slide barand locking means comprising a bar pivoted upon the bearing extensionand provided with means for holding the marking ruler in a perpendicularposition with relation to the horizontal ruler.

2. An instrument of the class described, comprising a horizontal ruler,a-track bar thereon, a slide bar mounted on the track bar, a bearingextension extending from the track bar, a marking ruler pivoted to thebearing extension and provided with a beveled convex inner end, a crossbar extending across the bottom face of the Ybearing exten'- sion andhaving a recessed inner edge to receive the inner end of the markingruler, means for locking the marking ruler in alinenient with thebearing extension and means for holding the ruler at different angularadjustments.

In testimony whereof I have hereunto set my hand in presence of twosubscribing wit- FRED. C. MILLER.

